The Amtrak Pacific Surfliner route between San Diego and LA runs 128 miles on the Pacific Coast. The Surfliner on this section has 20 services per day with the trains taking 3 hours to get between the two places. The fastest section on this route is in Carlsbad with the speed limit topping out at 90mph. There are some interesting formations you can see here sometimes. One of them being with 9 passenger cars and then 1 locomotive on each end. One formation you can see always though is the one with 6 passenger cars including cab car and just one locomotive on the front. The locomotives you could see on this the F59PHi, P42DC, and SC44. For much of the route, it is beautiful to look at because you are beside the ocean. Best times at sunset. Along the route though is a decent number of stations, like Salona Beach, Oceanside, Carlsbad, Irvine, Santa Ana, Fullerton, and somewhere else like San Juan Capistrano.
BNSF runs on this line, as does Coaster. I'd like a Coaster SC44 Charger and BNSF ET44C4, SD70ACe, ES44AC/DC/C4, or C44-9W for this route. A GP60 or GP60M-3 or a B40-8W would be perfect for BNSF local freights on the Surfliner route. Of course, we need the Surfliner Cab Cars, too.
Like every other Pacific Surfliner suggestion, I have to mention the line would lose a majority of its services due to the Metrolink and Coaster licensing issues, leaving the line only open to the 10 daily round trips between LA and SD, the Southwest Chief, and BNSF, mainly between Long Beach (Via the Alameda Corridor) to Fullerton Junction, as well as Hobart Yard and the many industries along that line. BNSF does operate all the way to San Diego, but those are only a handful of manifests, Auto trains, and the military movement of equipment for overseas training. Probably the only best option for Pacific Surfliner is a route from LA to Fullerton, with Amtrak and BNSF, since that area sees the most daily traffic, but then the route loses its picturesque scenery its known for along the coast. Its a no win situation without Metrolink or Coaster.
The route is at my backyard, so personally really wish it could come to TSW as I do own the respective route in TSC - licensing for metrolink and/or coaster is an issue, but an approach similar to the TSC Chicago Racetrack can be considered, having an unbranded "fake" train is better than having no train at all, although I also understand that the logo might be very important for some other players.
Unbranded content would receive a lot of backlash. Rivet tried it with island line 2022 where they used a fictional livery and some people hated the route cuz it was fake and that it wasn't acceptable when they are paying for it. It's not a bad route after all but some people will give a bad review just cuz of an incorrect livery. When things aren't realistic, people will complain. So creating a fictional metra livery wouldn't be met with good reception. People expect things to be realistic and correct when routes are already expensive.